Electrical connector



Dec. 4, 1962 c. R. RHODES 3,067,401

ELECTRICAL CONNECTOR Fi1edJu1y22,1959

CHESTER R RHODES AGENT Uite rates arent Y y 3,967,401` ELECTRICALCONNECTOR Chester R. Rhodes, 266 W. Stardeil, Whittier, Calif. FiledJuly 22, 1959, Sel'. No. 823,860* '7 Claims. (Cl. 339-63) My inventionrelates to a solderless type of electrical connector. It may befabricated to join only two electrical conductors or a plurality of suchindividual elements may be mounted to simultaneously secure or release aplurality of electrical conductors.

In electronic equipment and the like numerous separable electricalconnections are required between wires, plug-intype' relays, etc. Goodelectrical connection is necessary and this can be accomplished by asliding action of theconnecting elements each time the connection'ismade. It is also desirable that the restraint resisting a force toseparate the connection increase as a function of the magnitude of sucha force, that the reliability of the connection not be influenced bytemperature nor by vibration, that the connector be relativelyinexpensive to manufacture, and that it be separable with simple tools.

-I have been able to meet the above requirements by forming a somewhatilexible conductor into a loosely woven braid of tubular shape. Wires orother electrical elements to be connected are terminated by cylindricalpins which fit within the woven tube. After the insertion of the pinsinto the tube any attempt to pull them out,

as by means of the wires attached to the pins, causes the braid todeform to a smaller internal diameter. This causes the pins to be heldall the more rmly. This action continues until the structure ruptures atits weakest point, which may well be the wires rather than theconnector. On the other hand, if the pins are to be removed from thewoven sleeve to break the connection it is only necessary to decreasethe length of the sleeve with the fingers, or by means of a simplecompressive plier-like 4tool and the pins may be readily released.

Where a plurality of connections are to be made my individual connectorsare provided with planar members to hold the circuits as a group, and byemploying screws in association with such members all individualconnectors may be loosened or tightened at once.

-An object of my invention is to provide an electrical connector havinggreat mechanical resistance to separation by axial tension.

Another object is to provide a connector that assembles with a wipingaction of the contact surfaces.

Another object is to provide a connector that is minimally affected byvibration.

Another object is to provide a multiple electrical connector of simpleconstruction. n

Another object is to provide a connector that is relatively inexpensiveto manufacture.

Other objects will become apparent upon reading the following detailedspecification and upon examining the accompanying drawings, in which areset forth by way of illustration and example certain embodiments of myinvention.

FIG. 1 shows a sectional elevation View of an assembled individualconnector according to my invention.

FIG. 2 shows an end elevation of the outer woven tubular element alone,

FIG. 3 shows an alternate embodiment of a pin alone,

FIG. 4 shows a top view of a multiple connector,

FIG. 5 shows a side view of the same multiple connector, in partialsection, and

FIG. 6 shows a sectional elevation view of a detail of the structure ofFIG. 5.

In FIG. l numeral 1 indicates the loosely Woven mesh ice 2 or braid.This lis fabricated of a conductor of electricity, such as anymechanically str-ong worked copper or copper alloy, or this may be analloy of silver and copper having of the order of'7G% silver. Therequirements are; good contact conductivity and freedom from fatigue.

The contact pins from the circuits to be connected make contact throughthis braid and so the former requirement is obvious. The latterrequirement arises from the minor mechanical deformation that occurswhen the connector is separated and joined to accomplish disconnectionand reconnection. Many thousands of such operations may occur during theextended life of my device and Where this is the case the latterrequirement is irnportant.

Braid 1 is attached to annular disks or rings 2 at each end in orderthat the braid shall not ravel. The attachment may be accomplished bysoldering, welding or crimping. As shown in FIG. 2 I prefer to provide aradial slot 3 completely through disks 2. These disks are then formed topresent a tight t to the contact pins when these are inserted throughthe hole thereof. When the pins are inserted the disk is slightlyexpanded. This is a manufacturing convenience that removes therequirements of close tolerances between the diameters of the pins andthe diameter of the hole in the ring.

Pins 4 and 5 form the other mechanical elements to accomplish electricalconnection between the two external conductors. These are each providedwith an axial hole or equivalent reentrant construction (not shown inFIG. l) to receive external conductors 6 and 7, respectively. Inordinary practice these conductors would merely be soldered into holesin pins 4 and 5. For high temperature applications, or for manufacturingconvenience, the wires may instead be Welded or crimped to the pins.Insulating coverings 8 and 9 have been shown on conductors 6 and 7 asillustrative of a most frequent application of my invention. The pinsmay be fabricated of brass or bronze and may be silver plated, etc. forsuperior contact performance.

My connector is held together by an external elastic element 10, capableof viscous contraction after elongation. This may be a tubing ofsilicone rubber. It ts over annular disks 2 with at least some bulge asshown, and is proportioned so as to elongate braid sleeve 1 when theelastic element is relaxed. In this condition the woven braid tightlyenfolds the pins and these cannot be pulled out of it. Should this beattempted, the braid grasps the pins even more tightly. This is thenormal connected configuration of elements and forces.

When it is desired to disconnect the connection elastic element 10 isshortened axially by pressing the ends together with the ngers of twohands, say; or by accomplishing an equivalent compression with a pair ofpliers having U shaped jaws to fit around the external conductorinsulations 8 and 9. From what has been previously mentioned it will beunderstood that the grip of the mesh sleeve will be removed and the pins4 and 5 may be pulled out of the connector with a small force. v

As an alternatesubstance, elastic element 10 may be certain of the newerplastics, such as foam, styrene or certain exible epoxys having elasticproperties; or even Teon may be employed. The function of element 10 isto keep the tubular braid tight around the pins when there is no tensionon the conductors by supplying the equivalent of such tension. This needbe only a minor force and so a substance not always regarded as arubber-like material may be employed.

An alternate construction for the pins is shown in FIG. 3. Themodification consists of the enlarged portion 12 formed on pin 14. Thisportion acts as an additional securing means. The tubular braid formsaround the ahem/s1 enlarged portion and so the security of the pin inthe connector is greater than with the previously described purelycylindrical pin. The position of the enlarged portion along the lengthof the pin may be any of a number, starting at the free end (to theright in FIG. 3) to relatively toward the conductor end of the pin. Thelatter end is identified in FIG. 3 by the axial hole 15. When enlargedportion 12 is at the free end on both of the opposed pins in a connectorsuch as shown in FIG. 1, both act to form one portion'of enlargeddiameter in the tubular braid. When the enlargements are spaced apart,asin the one example of FIG. 3, two enlarged portions of the braid result.

FIG. 4 shows the top view of a multiple connector and FIG. 5 theelevation thereof. Substantially the same connectors as shown in FIG. 1are either pressed into suitable holes in a body or central plate 16, orare molded into the same. The latter is preferable. This body isnormally formed of a mechanically strong insulator, such as diallylphthalate 'or an equivalent. This body could be a conductor, since theseveral individual connectors each have a non-conducting elastic element18 as a surround, which serves to insulate one from the other. Theseelastic elements diier Afrom elastic element in that these do notYextend to the ends of the connector assembly.

In this multiple embodiment I prefer to obtain securing and unsecuringaction by means of thumb screws or cap screws 19 for accomplishing thisfunction on one side of the connector and screws 26 on the other-side.This allows separate connection or disconnection on opposite sides. Inaddition to merely connecting wires with my multiple connector it willbe understood that pin type relays may be insertedon the top (or thebottom) of the multiple connector, with wires out the opposite side.Thus, if it is desired to replace one or more relays, one side oftheconnector is loosened; if to replace one or more wires, the Otherside is loosened. The central plate or body has projecting ends and isidentified by numeral'l.v Holes 17 are formed in these ends for mountingthe multiple connector as a whole.

.In the multiple connector embodiment two end plates 21 and 22, areemployed, into which the ends of the tubu lar braid individualconnectors are tightly fitted. The top annular disks 23 may be seen inFIG. 4, which figure corresponds to a multiple version of FIG. 2. Eachend plate is providedl with threaded holes to accommodate threads oneach screw, as 19, shown in the right-hand partial section in FIG; 5. Ifthe plate is fabricated of a mechanically strong insulator, the threadsmay be formed y in that material, but a threaded metal insert is to bepreferred. It is seen that when the screws are turned in one directionthe end plates are forced away from the center plate and when turned inthe other direction the reverse is true. The rst (outward) positioncorresponds to the pins locked in the tubular braid, while the second(compressed) position corresponds to the connectors expanded in diameterand thusthe pins free to be removed. In order thatv the screws remaincaptive and not become lost I place washers 24 on each and then swageears 25 beyond on the non-threaded end of the screws to retainv thewashers. i

I prefer to mold or to otherwise provide a pair of ribs integral witheach end plate. These are identified as 26 and 27 for the upper endplate and 28 and 29 for the lower. Such ribs provide very eifectivestiiening. Although the multiple connector will function satisfactorilywithout precise alignments it is desirable to have each of therelatively rigid members remain in substantially xed shape. It will alsobe understood that such ribs mayy also be located on the outer sides ofthe end plates. In such a position they act as battles between onemultiple connector and another. Ribs may also be located on both theinside and the outside faces of the end plates, .and may be included onthe Vcenter plate 16 is desired.

I also prefer to include a plurality of guide pins 30 for maintainingalignment of the end plates with the central plate or body. Such guidepins are a tight fit in the central plate 16 and sliding fits in plates21 and 22. Four guide pins have been shown in FIG. 4. Two, lof course,could be used; located at opposite corners of the plates. Also, fourscrews 19 and four screws 20 may be used at the four corners and onlytwo centrally located guide pins 30 located where screws 19 and 20 arelnot located.

It is apparent that my multiple connector can be fabricated for as fewas two connections, for eighteen con nections as shown, or for anynumber up to hundreds of connections. In the latter construction, screws19 and 20 are included at repeated intervals along the plates. Theplates may have any shape and any arrangement of individual connectorsthereon.

A further modification of the multiple connector of FIGS. 5 and 4 isshown fragmentarily in FIG. 6. In this embodiment each tubular braid isarranged so as to have a limited amount of lateral self-adjustment. Thisis to accommodate the pins of a plug-in relay or the like, which pinsare lixed in position.

y:Numeral 33 represents a fragment of one end plate. This is drilled toreceive a tubular braid 34 and annular disk 35. Above this disk a ring36 `is pressed into plate .33. The ring is made a tight fit radially inthe plate, but axially of the tubular braid 34 sufficient clearance isar` ranged to allow the annular disk to shift laterally in position.This accommodates any particular mis-positioning of relay pins, whichcondition is to be expected in ordinary manufacturing or for otherreasons.

It will be understood that the axial clearance desired of ring 36 may bedetermined by the form of the hole in plate 33. A slightly largerdiameter hole can be drilled in the upper part of this plate and ring 36is made slightly larger so that it will tit in the upper part of thehole but not farther down thereinto. A flat-bottomed reamer or anequivalent special tool is employed to obtain a planar face at thebottom of the step in this modified hole.

Should it be desired to enclose the multiple connector of FIGS. 4 and 5,this can be accomplished by providing an outer housing of substantiallyrectangular shape. Partial enclosure can be accomplished by merelyproviding ribs toward the central plate on both end plates around theperiphery of each. Such ribs may not extend all the way to the centerplate because of the variation in distance between the plates duringt-he connection and disconnection processes. Very nearly the same resultmay be obtained, however, by adding ribs on both sides of the centralplate but at slightly different positions so that the two sets of ribson the end plates and on the central plate slide past Veach other whenthese plates are brought together for disconnection purposes.

Rather than one mounting hole 17 at each end of the body or centralplate, two or more such holes may be provided by extending'the' plateinto a rectangular shape and forming the holes in thel corners of therectangle, andsoy on. v

While a selvage at the'end of the woven conductive element 1 has beenshown as an attached metal annulus, the selvage can be formed byredundancy in the weaving alone at the ends of this tubular braid.

Also, the expanded portion 12 in FIG. 3 may take the form of a taperalong the pin 14, with the taper largest at the right hand end of theligure.

It is not mandatory that the elastic element 10' overhang the annuluspieces 2 in FIG. 1.

In addition to the modifications that have been detailed above, variousother modifications may be made in the arrangement, size, proportionsand shapes of the illustrative embodiments shown and also by thesubstitution of elements from one embodiment to another withoutdeparting yfrom the scope of my invention.

Having thus fully described my invention and the manner in which it isto be practiced, I claim:

1. An electrical connector comprising plural hollow elements ofconductive Woven braid, an elastic element surrounding each said braid,conductive elements proportioned to it oppositely into said hollowelements, a body having a hole to receive each said elastic element, anend plate disposed on cach side of said body, one end of each saidhollow element tightly attached to one said end plate with lateral play,each said end plate having opposed adjustable means bearing onto saidbody; the recited elements proportioned so that when the pluralconnector structure is 1in-stressed said conductive elements are free tobe withdrawn from said hollow elements and when said opposed means arestressed said conductive elements are held within said hollow elements.

2. A multiple electrical connector comprising plural individualconnectors each having a tubular conductive woven braid with annularends, a resilient tubing closely surrounding said braid, conductiveconnector pins, said pins proportioned to lit into said braid, a centralplate having a hole to separately receive each said tubing, an end platedisposed on each side of said central plate, each end plate having ahole to receive and secure one of said annular ends of each said braidin an alignment perpendicular to said plates, each said end plate havingscrews threaded into said end plate and bearing onto said central platein opposition, plural guide pins passing through said plates to maintainsaid tubular braids in axial alignment; the recited elementsproportioned so that when said screws are withdrawn from contact withsaid central plate said pins are free to be withdrawn from said braidsand so that when said screws are tightened against said central platethe braids each grip the pins therewithin.

3. A multiple electrical connector comprising plural individualconnectors, each said individual connector having a tubular conductiveopen mesh woven braid with annular ends, a resilient tubing closelysurrounding each said braid, conductive pins attachable to electricalelements to be connected, said pins proportioned to tit into each end ofsaid braid, a central plate having a hole to receive each said resilienttubing in spaced relation, an end plate disposed on each side of saidcentral plate in planes parallel to the plane of said central plate,each end plate having a hole to tightly receive one of said annular endsof each said braid in alignment perpendicular to the planes of saidplates, each said end plate having plural captive screws threaded intosaid end plate and bearing onto said central plate in aligned opposingmanner, plural guide pins fastened in said central plate and having asliding t in said end plates to maintain each said tubular braid inaxial alignment; the recited elements proportioned so that when themultiple connector structure is unstressed the pins are free to bewithdrawn from said braids because of the relaxed length of saidresilient tubing but that when said screws are tightened said braids areeach elongated to firmly grip the pins therewithin.

4. The electrical connector of claim 1 in which said proportionedconductive elements are shaped with an enlarged cross-sectional area fora portion of the axial length thereof, said conductive woven braidformed to said shape by the force exerted upon each said braid by theelastic element surrounding it.

5. The electrical connector of claim 1 in which the structure forallowing said lateral play comprises a hole in said end plate having alarger diameter than the diameter of said hollow element and a ringsurrnounting said hollow element, said ring attached to said end plateto form a cavity therein for allowing lateral play of said hollowelement in said end plate.

6. The electrical connector of claim 1 in which said end plate has atleast one rib extending from the surface of said end plate and lyingbetween said plural hollow elements to stillen said end plate.

7. The electrical connector of claim l in which said end plate has atleast one rib extending from the surface of said end plate on the sidetoward said body to stiften said end plate.

References Cited in the ille of this patent UNITED STATES PATENTS2,189,987 Kellems Feb. 13, 1940 2,266,214 Kellems Dec. 16, 19412,310,212 Buchanan Feb. 9, 1943 2,434,358 Frank Jan. 13, 1948 2,690,541Elliott Sept. 28, 1954 2,755,449 Anderson July 17, 1956 2,814,024Norozny Nov. 19, 1957 2,845,604 Jackson ct al July 29, 1958 2,896,186Hardmark July 2l, 1959 FOREIGN PATENTS 597,134 Germany May 17, 1934694,985 Great Britain luly 29, 1953

